U.S. patent number 9,417,143 [Application Number 14/199,081] was granted by the patent office on 2016-08-16 for apparatus and method for measuring bending of an object, by using an optical waveguide.
This patent grant is currently assigned to Samsung Electronics Co., Ltd.. The grantee listed for this patent is Samsung Electronics Co., Ltd.. Invention is credited to Seung Ju Han, Hyun Jeong Lee, Soo Chul Lim, Kyung Won Moon, Joon Ah Park.
United States Patent |
9,417,143 |
Lim , et al. |
August 16, 2016 |
Apparatus and method for measuring bending of an object, by using
an optical waveguide
Abstract
An apparatus and method for measuring bending of an object, a
position of an item touching the object, and a shearing force of
the item using an optical waveguide may include a frequency
measurer to measure a frequency of light reflected from a grating
of an optical waveguide, and a bending measurer to determine
bending of an object to which the optical waveguide is attached
using the frequency.
Inventors: |
Lim; Soo Chul (Seoul,
KR), Park; Joon Ah (Seoul, KR), Lee; Hyun
Jeong (Hwaseong-si, KR), Han; Seung Ju (Seoul,
KR), Moon; Kyung Won (Yongin-si, KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
Samsung Electronics Co., Ltd. |
Suwon-si |
N/A |
KR |
|
|
Assignee: |
Samsung Electronics Co., Ltd.
(Suwon-si, KR)
|
Family
ID: |
51864847 |
Appl.
No.: |
14/199,081 |
Filed: |
March 6, 2014 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20140334767 A1 |
Nov 13, 2014 |
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Foreign Application Priority Data
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May 13, 2013 [KR] |
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10-2013-0053821 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01L
1/246 (20130101); G06F 3/0421 (20130101); G01L
5/105 (20130101) |
Current International
Class: |
G01D
5/353 (20060101); G06F 3/042 (20060101); G01L
1/24 (20060101); G06F 3/041 (20060101); G01L
5/10 (20060101) |
Field of
Search: |
;385/16-24,13 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2003-500654 |
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Jan 2003 |
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JP |
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2004-506869 |
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Mar 2004 |
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JP |
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10-2011-0092611 |
|
Aug 2011 |
|
KR |
|
10-2011-0092614 |
|
Aug 2011 |
|
KR |
|
10-2012-0065925 |
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Jun 2012 |
|
KR |
|
Other References
X Chen et al., "Optical bend sensor for vector curvature
measurement based on Bragg grating in eccentric core polymer
optical fibre", 20.sup.th International Conference on Optical Fibre
Sensors, Proc. of SPIE vol. 7503, 750327-1, 2009, 4 pages. cited by
applicant .
Timothee Boitouzet et al., "Fiber Optic Bend Sensors", Crafting
Material Interfaces, Oct. 2011, URL
http://material.media.mit.edu/?p=750. cited by applicant.
|
Primary Examiner: Ullah; Akm Enayet
Attorney, Agent or Firm: NSIP Law
Claims
What is claimed is:
1. A measuring apparatus comprising: a frequency measurer
configured to measure a frequency of light reflected from a grating
of an optical waveguide, wherein the grating comprises grating
grooves; and a bending measurer configured to determine, by using
the measured frequency, bending of an object to which the optical
waveguide is attached, wherein when a portion of the measured
frequency of light reflected from the grating grooves is changed,
the bending measurer is configured to identify a position of a
grating groove among the grating grooves corresponding to the
changed frequency, and to determine that bending has occurred at
the identified position.
2. The measuring apparatus of claim 1, wherein when the measured
frequency is increased, the bending measurer is configured to
determine that bending has occurred at the object in an expansion
direction of the optical waveguide.
3. The measuring apparatus of claim 1, wherein when the measured
frequency is decreased, the bending measurer is configured to
determine that bending has occurred at the object in a contraction
direction of the optical waveguide.
4. The measuring apparatus of claim 1, wherein the grating
comprises first grating grooves arranged in a first direction and
second grating grooves arranged in a second direction, and the
frequency of light reflected from the first and/or second grating
grooves is measured according to positions of the grating
grooves.
5. The measuring apparatus of claim 1, wherein the bending measurer
is configured to determine a degree of bending based on a change in
a degree of the measured frequency.
6. The measuring apparatus of claim 1, further comprising a
position and shearing measurer configured to determine, by using
the measured frequency, a position and a shearing force of an item
touching the optical waveguide.
7. The measuring apparatus of claim 6, wherein when a change in a
degree of the measured frequency is smaller than or equal to a
threshold, the position and shearing measurer is configured to
identify a position of a grating groove corresponding to the
changed frequency, and is configured to determine that the item
touches the object at the identified position.
8. The measuring apparatus of claim 6, wherein the position and
shearing measurer is configured to determine the shearing force of
the item, based on a change in a direction of the measured
frequency.
9. A measuring apparatus comprising: a frequency measurer
configured to measure frequency of light reflected from a grating
of an optical waveguide, wherein the grating comprises grating
grooves; and a position and shearing measurer to determine, by
using the measured frequency, a position and a shearing force of an
item touching the optical waveguide, wherein when a portion of the
measured frequency of light reflected from the grating grooves is
changed, the position and shearing measurer is configured to
identify a position of a grating groove among the grating grooves
corresponding to the changed frequency, and to determine that
bending has occurred at the identified position.
10. The measuring apparatus of claim 9, wherein when the measured
frequency is changed, the position and shearing measurer is
configured to identify a position of a grating groove corresponding
to a changed frequency, and is configured to determine that the
item touches the optical waveguide at the identified position.
11. The measuring apparatus of claim 9, wherein when a frequency
reflected from at least one of the grating grooves is reduced and a
frequency reflected from another of the grating grooves is
increased, the position and shearing measurer is configured to
determine the shearing force of the item, based on a position of
the at least one of the grating grooves of which a frequency is
reduced, and a position of the another of the grating grooves of
which a frequency is increased.
12. The measuring apparatus of claim 11, wherein the position and
shearing measurer is configured to determine, as a direction of the
shearing force, a direction from the at least one of the grating
grooves of which the frequency is reduced to the another of the
grating grooves of which the frequency is increased.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the priority benefit of Korean Patent
Application No. 10-2013-0053821, filed on May 13, 2013, in the
Korean Intellectual Property Office, the disclosure of which is
incorporated herein by reference.
BACKGROUND
1. Field
The following description relates to an apparatus and method for
measuring bending and touch using an optical waveguide, and more
particularly, to an apparatus and method for measuring bending of
an object to which an optical waveguide is attached, or a position
and a shearing force of a item touching the object, using a
frequency of light reflected from grating of the optical
waveguide.
2. Description of the Related Art
Recently, a touch input method is widely used, which enables input
of data by touching a screen without a dedicated input tool.
A touch input device included in conventional mobile phones or
mobile terminals detects a touch between the screen and a human
hand or pen or measures a vertical pressure applied to the screen,
and uses a measurement result as input data.
However, because the conventional touch input device measures only
the vertical pressure, reliability of a shearing force measured
with respect to an object moving horizontally is relatively
low.
In addition, when a flexible display capable of bending is used,
bending and a bending degree of the flexible display may not be
detected by only measurement of the vertical pressure.
Accordingly, there is a need for a measuring apparatus for
measuring bending of a display and a shearing force of an item
touching the display.
SUMMARY
The foregoing and/or other aspects are achieved by providing a
measuring apparatus including a frequency measurer to measure a
frequency of light reflected from a grating of an optical
waveguide, and a bending measurer to determine bending of an object
to which the optical waveguide is attached using the frequency.
The bending measurer may determine that bending has occurred at the
object in an expansion direction of the optical waveguide when the
frequency is increased.
The bending measurer may determine that bending has occurred at the
object in a contraction direction of the optical waveguide when the
frequency is decreased.
When a part of the frequency of light reflected from the grating
grooves is changed, the bending measurer may identify a position of
a grating groove corresponding to the changed frequency, and
determine that bending has occurred at the identified position.
The bending measurer may determine a degree of bending based on a
change degree of the frequency.
The measuring apparatus may further include a position and shearing
measurer to determine a position and a shearing force of an item
touching the optical waveguide using the frequency.
The foregoing and/or other aspects are also achieved by providing a
measuring apparatus including a frequency measurer to measure
frequency of light reflected from a grating of an optical
waveguide, and a position and shearing measurer to determine a
position and a shearing force of an item touching the optical
waveguide using the frequency.
The position and shearing measurer may identify a position of a
grating groove corresponding to a changed frequency when the
frequency is changed, and determine that the item touches the
object at the identified position.
The position and shearing measurer may determine the shearing force
of the item based on a change direction of at least one frequency
when at least one of the frequencies are changed.
The foregoing and/or other aspects are also achieved by providing a
measuring method including measuring a frequency of light reflected
from a grating of an optical waveguide, and measuring bending of an
object to which the optical waveguide is attached, using the
frequency.
The foregoing and/or other aspects are also achieved by providing a
measuring method comprising measuring a frequency of light
reflected from a grating of an optical waveguide, and measuring a
position and shearing force of a item touching the optical
waveguide using the frequency.
Additional aspects, features, and/or advantages of example
embodiments will be set forth in part in the description which
follows and, in part, will be apparent from the description, or may
be learned by practice of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
These and/or other aspects and advantages will become apparent and
more readily appreciated from the following description of the
example embodiments, taken in conjunction with the accompanying
drawings of which:
FIG. 1 illustrates a configuration of a measuring apparatus
according to example embodiments;
FIG. 2 illustrates an object to which an optical waveguide is
attached, according to example embodiments;
FIG. 3 illustrates a state change of an optical waveguide in a case
in which a flexible display to which the optical waveguide is
attached is bent downward, according to example embodiments;
FIG. 4 illustrates a state change of an optical waveguide in a case
in which a flexible display to which an optical waveguide is
attached is bent upward, according to example embodiments;
FIG. 5 illustrates a state change of an optical waveguide in a case
in which a flexible display to which the optical waveguide is
attached is partially bent, according to example embodiments;
FIG. 6 illustrates a configuration of a measuring apparatus
according to example embodiments;
FIG. 7 illustrates an object to which an optical waveguide is
attached according to example embodiments;
FIG. 8 illustrates an example of measuring a shearing force of an
item touching an optical waveguide, according to example
embodiments;
FIG. 9 illustrates a state change of an optical waveguide according
to a shearing force of an item, according to example
embodiments;
FIG. 10 illustrates a process of measuring a position of an item
touching an optical waveguide, according to example
embodiments;
FIG. 11 illustrates a bending measurement method according to
example embodiments; and
FIG. 12 illustrates a pressure measurement method according to
example embodiments.
DETAILED DESCRIPTION
Reference will now be made in detail to example embodiments,
examples of which are illustrated in the accompanying drawings,
wherein like reference numerals refer to like elements throughout.
Example embodiments are described below to explain the present
disclosure by referring to the figures.
FIG. 1 illustrates a configuration of a measuring apparatus 100
according to example embodiments.
Referring to FIG. 1, the measuring apparatus 100 may include an
optical waveguide 110, a frequency measurer 120, a bending measurer
130, and a position and shearing measurer 140.
The optical waveguide 110 may include a Bragg grating array, for
example. When an optical wavelength of a wide band, passing through
the optical waveguide 110, comes into contact with grating of the
optical waveguide 110, light of a particular frequency may be
reflected from the grating. A frequency of the light reflected by
the grating may be varied according to an interval of grating
grooves of the grating.
The optical waveguide 110 may be a polymer-based optical waveguide
included in a flexible film capable of being bent or deformed by an
external pressure. For example, the flexible film may include a
polymer such as polydimethylsiloxane (PDMS) or fluorinated poly
(arylene ether) (FPAE).
When the flexible film including the optical waveguide 110 is bent
or pressurized, the optical waveguide 110 may also be bent or
pressurized, and therefore, the interval of the grating grooves
formed at the optical waveguide 110 may be changed. Accordingly,
when the flexible film including the optical waveguide 110 is bent
or pressurized, a frequency of light reflected from the respective
grating grooves of the optical waveguide 110 may also be
changed.
Here, the grating of the optical waveguide 110 may include
pluralities of grating grooves arranged in a first direction and a
second direction, such as a vertical direction and a horizontal
direction, for example. The frequency of the light reflected from
the grating grooves may be determined by the positions of the
individual grating grooves. However, the disclosure is not limited
thereto. For example, the pluralities of grating grooves may be
arranged in any direction or directions that allow a position to be
determined, such as in a diagonal direction, for example.
A configuration of the optical waveguide 110 will be described in
detail with reference to FIG. 2.
The frequency measurer 120 may measure the frequency of the light
reflected from the grating grooves of the optical waveguide
110.
The bending measurer 130 may determine bending of the object to
which the optical waveguide 110 is attached, using the frequency
being measured. For example, the object may be a flexible display
capable of bending.
In detail, when the frequency measured by the frequency measurer
120 is increased, the bending measurer 130 may determine that
bending has occurred at the object in an expanding direction of the
optical waveguide 110.
Operation of when the bending occurs at the object in the expanding
direction of the optical waveguide 110 will be described in detail
with reference to FIG. 4.
When the frequency measured by the frequency measurer 120 is
decreased, the bending measurer 130 may determine that bending has
occurred at the object in a contracting direction of the optical
waveguide 110.
Operation of when the bending occurs at the object in the
contracting direction of the optical waveguide 110 will be
described in detail with reference to FIG. 3.
When a portion of the frequency of the light reflected from the
grating grooves is changed, the bending measurer 130 may identify a
position of the grating grooves corresponding to the changed
frequency and determine that bending has occurred at the identified
position.
Operation of when a portion of the optical waveguide 110 is bent
will be described in detail with reference to FIG. 5.
Here, the bending measurer 130 may determine a degree of bending of
the object based on a change in a degree of the frequency measured
by the frequency measurer 120. For example, when the frequency
measured by the frequency measurer 120 is changed by a relatively
large degree, the bending measurer 130 may determine that the
object is bent by a large degree.
The position and shearing measurer 140 may determine a position and
a shearing force of an item touching the optical waveguide 110,
using the frequency measured by the frequency measurer 120.
When the change in a degree of the frequency measured by the
frequency measurer 120 is not greater than a threshold, the
position and shearing measurer 140 may determine that the frequency
change is caused not by bending of the object, but by an item
touching the optical waveguide 110 coupled with the object.
Therefore, when the change in a degree is not greater than the
threshold, the position and shearing measurer 140 may identify the
position of the grating groove corresponding to the changed
frequency and determine that the item touches the optical waveguide
coupled with the object at the identified position.
A process of measuring a position of the item touching the optical
waveguide 110 by the position and shearing measurer 140 will be
described in detail with reference to FIG. 10.
Here, the position and shearing measurer 140 may determine the
shearing force of the item based on a change direction of the
frequency measured by the frequency measurer 120. The shearing
force of the item may refer to a force applied horizontally toward
the optical waveguide 110 by the item touching the optical
waveguide 110. For example, the shearing force may be one of a
force generated in a particular direction when the item is moved in
the particular direction and a force applied by the item in an
unmoving state.
A process of measuring the shearing force of the item touching the
optical waveguide 110 by the position and shearing measurer 140
will be described in detail with reference to FIG. 9.
FIG. 2 illustrates an object to which an optical waveguide 210 is
attached, according to example embodiments.
The optical waveguide 210 according to the example embodiments may
be included in a flexible film 200 as shown in FIG. 2.
The optical waveguide 210 may include a plurality of grating
grooves 211 arranged in a vertical direction of the flexible film
200 and a plurality of grating grooves 212 arranged in a horizontal
direction of the flexible film 200.
The flexible film 200 may be transparent, but is not limited
thereto. The transparent flexible film 200 may be attached to a
flexible display 220 capable of bending to be used as an input
device of the flexible display 220.
The measuring apparatus 100 may determine at least one of a touch
input, a bending input, and an input using a shearing force, that
is, a shearing force input, of a user, using the grating 211 or a
frequency of light reflected from the grating 212.
In detail, when the frequency change is smaller than a
predetermined threshold, the measuring apparatus 100 may determine
that the user makes the touch input or the shearing force input,
and determine a position touched by the user or a position and
direction of the shearing force input, using the position of the
grating groove corresponding to the changed frequency.
When the frequency change is greater than the predetermined
threshold, the measuring apparatus 100 may determine that the user
makes the bending input, and determine a direction and degree of
the bending of the flexible display 200 according to a direction
and degree of the frequency change of the light.
FIG. 3 illustrates a state change of an optical waveguide 310 in a
case in which a flexible display 320 to which the optical waveguide
310 is attached is bent downward, according to example
embodiments.
As in Case 1, a flexible film 300 including the optical waveguide
310 may be attached to an upper surface of the flexible display
320. A plurality of grating grooves 311 included in the optical
waveguide 310 may reflect light of different frequency bands,
respectively.
When the flexible display 320 is bent downward as in Case 2, the
grating grooves 311 of the optical waveguide 310 may be provided
with a pressurizing force. Therefore, intervals of the grating
grooves 311 of the optical waveguide 310 may be reduced in
comparison to intervals of Case 1. Also, the frequency reflected by
the grating grooves 311 may be reduced according to the reduction
in the intervals of the grating grooves 311.
When a frequency measured by the frequency measurer 120 in Case 2
is smaller than a frequency measured by the frequency measurer 120
in Case 1, the bending measurer 130 of the measuring apparatus 100
may determine that bending has occurred in a contracting direction
of the optical waveguide 310. Here, because the contracting
direction of the optical waveguide 310 is opposite to a direction
in which the flexible film 300 is attached as shown in FIG. 3, the
bending measurer 130 may determine that the flexible display 320 is
bent in an opposite direction to the direction in which the
flexible film 300 is attached.
In addition, the bending measurer 130 may calculate a difference
between the frequency measured by the frequency measurer 120 in
Case 1 and the frequency measured by the frequency measurer 120 in
Case 2, and determine the bending degree of the flexible display
320 based on the calculated difference.
FIG. 4 illustrates a state change of an optical waveguide 410 in a
case in which a flexible display 420 to which an optical waveguide
410 is attached is bent upward, according to example
embodiments.
As shown in Case 1, a flexible film 400 including the optical
waveguide 410 may be attached to an upper surface of the flexible
display 420 capable of bending. A plurality of grating grooves 411
included in the optical waveguide 410 may reflect light of
different frequency bands, respectively.
When the flexible display 420 is bent upward as in Case 2, the
grating grooves 411 of the optical waveguide 410 may be applied
with an expanding force. Therefore, intervals of the grating
grooves 411 may be increased in comparison to intervals of Case 1.
Also, the frequency reflected by the grating grooves 411 may be
increased according to the reduction in the intervals of the
grating grooves 411.
When the frequency measured by the frequency measurer 120 in Case 2
is greater than the frequency measured by the frequency measurer
120 in Case 1, the bending measurer 130 of the measuring apparatus
100 may determine that bending has occurred in an expanding
direction of the optical waveguide 410. Here, because the expanding
direction of the optical waveguide 410 corresponds to the direction
in which the flexible film 400 is attached as shown in FIG. 4, the
bending measurer 130 may determine that the flexible display 420 is
bent in the direction in which the flexible film 400 is
attached.
In addition, the bending measurer 130 may calculate a difference
between the frequency measured by the frequency measurer 120 in
Case 1 and the frequency measured by the frequency measurer 120 in
Case 2, and determine the bending degree of the flexible display
420 based on the calculated difference.
FIG. 5 illustrates a state change of an optical waveguide 510 in a
case in which a flexible display to which the optical waveguide 510
is attached is partially bent, according to example
embodiments.
As shown in Case 1, a flexible film 500 including the optical
waveguide 510 may be attached to an upper surface of the flexible
display 520 capable of bending. A plurality of grating grooves 511
included in the optical waveguide 510 may reflect light of
different frequency bands, respectively.
When the flexible display 520 is partially bent as in Case 2, a
portion of the grating grooves 511 of the optical waveguide 510 may
be expanded or contracted. In detail, a grating groove 512 may be
contracted by bending of the flexible display 520 while neighboring
grating grooves 513 and 514 are not contracted.
Here, out of the frequency measured by the frequency measurer 120,
a frequency of a band corresponding to the grating groove 512 may
be changed. Therefore, the bending measurer 130 may identify a
position of the grating groove 512, of which the frequency is
changed, and determine that the flexible display 520 is bent at the
position of the grating groove 512.
Also, the bending measurer 130 may determine a direction and degree
of bending of the flexible display 520 by comparing the frequency
measured by the frequency measurer 120 in Case 1 and the frequency
measured by the frequency measurer 120 in Case 2.
FIG. 6 illustrates a configuration of a measuring apparatus 600
according to example embodiments.
FIG. 6 shows the configuration of the measuring apparatus 600 that
measures a position and a shearing force of an item touching a
device when a flexible film including an optical waveguide 610 is
attached to the device which is not bendable, such as a general
mobile device.
Referring to FIG. 6, the measuring apparatus 600 may include an
optical waveguide 610, a frequency measurer 620, a bending measurer
630, and a position and shearing measurer 640.
The optical waveguide 610 may include a Bragg grating array, for
example. When an optical wavelength of a wide band, passing through
the optical waveguide 610, comes into contact with grating of the
optical waveguide 610, light of a particular frequency may be
reflected from the grating. A frequency of the light reflected by
the grating may be varied according to an interval of grating
grooves of the grating.
The optical waveguide 610 may be a polymer-based optical waveguide
included in a flexible film capable of being bent or deformed by an
external pressure. For example, the flexible film may include a
polymer such as PDMS or FPAE.
When the flexible film including the optical waveguide 610 is
pressurized, the optical waveguide 610 may also be pressurized and
therefore the interval of the grating grooves formed at the optical
waveguide 610 may be changed. Accordingly, when the flexible film
including the optical waveguide 610 is pressurized, a frequency of
light reflected from the respective grating grooves of the optical
waveguide 610 may also be changed.
Here, the grating of the optical waveguide 610 may include
pluralities of grating grooves arranged in a vertical direction and
a horizontal direction. The frequency of the light reflected from
the grating grooves may be determined by the positions of the
individual grating grooves.
A configuration of the optical waveguide 610 will be described in
detail with reference to FIG. 7.
The frequency measurer 620 may measure the frequency of the light
reflected from the grating grooves of the optical waveguide
610.
The position and shearing measurer 630 may determine a position and
a shearing force of the item touching the optical waveguide 610,
using the frequency measured by the frequency measurer 620.
In detail, the position and shearing measurer 630 may check whether
the frequency measured by the frequency measurer 620 is changed. In
addition, when the frequency is changed, the position and shearing
measurer 630 may identify a position of the grating groove
corresponding to the changed frequency and determine that bending
has occurred at the identified position.
A process of measuring the item touching the optical waveguide 610
by the position and shearing measurer 630 will be described in
detail with reference to FIG. 10.
Also, the position and shearing measurer 630 may determine a
shearing force of the item based on a change direction of the
frequency measured by the frequency measurer 620.
In detail, when a frequency reflected from at least one of the
grating grooves is reduced and a frequency reflected from at least
one of the grating grooves is increased, the position and shearing
measurer 630 may determine the shearing force of the item based on
a position of a grating groove of which the frequency is reduced
and a position of a grating groove of which the frequency is
increased.
Here, the position and shearing measurer 630 may determine a
direction from the grating groove of which the frequency is reduced
to the grating groove of which the frequency is increased, as a
direction of the shearing force.
The position and shearing measurer 630 may determine a degree of
the shearing force of the item based on a decrease or an increase
of the frequency at the grating groove.
A process of measuring the shearing force of the item touching the
optical waveguide 610 by the position and shearing measurer 630
will be described in detail with reference to FIG. 9.
FIG. 7 illustrates an object to which an optical waveguide 710 is
attached according to example embodiments.
As shown in FIG. 7, a flexible film 700 including the optical
waveguide 710 may be attached to a display of a mobile apparatus
720. The flexible film 700 may be transparent and used as an input
device using the display of the mobile apparatus 720.
The optical waveguide 710 may include a plurality of grating
grooves 711 arranged in a vertical direction of the flexible film
700 and a plurality of grating grooves 712 arranged in a horizontal
direction of the flexible film 700.
A measuring apparatus according to the example embodiments may
determine at least one of a touch input of the user and an input
using a shearing force, using a frequency of light reflected from
the grating grooves 711 or the grating grooves 712.
In detail, when the frequency reflected from the grating grooves
711 or the grating grooves 712 is changed, the measuring apparatus
700 may determine a position touched by the user, or a direction
and degree of the shearing force, using the positions of the
grating grooves corresponding to the changed frequency.
FIG. 8 illustrates an example of measuring a shearing force of an
item touching an optical waveguide, according to example
embodiments.
As shown in FIG. 8, the user may apply a force in a right direction
with a finger 800 where the finger 800 touches a flexible film
including the optical waveguide.
In this case, a frequency of a grating groove 810 disposed in a
direction of applying the force may be reduced whereas a frequency
of a grating groove 820 disposed in an opposite direction to the
direction of applying the force may be increased.
Therefore, the position and shearing measurer 140 or the position
and shearing measurer 630 may determine an input of a shearing
force in a right direction from the finger 800 based on a frequency
change of the grating groove 810 or the grating groove 820.
A frequency reduction degree of the grating groove 810 and a
frequency increase degree of the grating groove 820 may be
proportional to the force applied by the finger 800 by the
user.
Therefore, the position and shearing measurer 140 or the position
and shearing measurer 630 may determine a degree of the shearing
force input by the finger 800 based on a degree of the frequency
change of the grating groove 810 and the grating groove 820.
FIG. 9 illustrates a state change of an optical waveguide according
to a shearing force of an item, according to example
embodiments.
The user may bring a finger 930 into contact with a flexible film
900 including an optical waveguide 910 as shown in Case 1.
Additionally, the user may apply a force in a right direction where
the finger 930 pushes the flexible film 900 as shown in Case 2.
Here, because the flexible film 900 is pushed in a right direction,
an area of the flexible film 900 disposed on the right of the
finger 930 may be contracted while an area of the flexible film 900
disposed on the left of the finger 930 may be expanded.
Therefore, grating grooves 912 disposed on the right of the finger
930 may be applied with a contraction force as the area of the
flexible film 900 disposed on the right of the finger 930 is
contracted. Accordingly, intervals of the grating grooves 912 may
be reduced in comparison to intervals of Case 1. Also, a frequency
reflected from the grating grooves 912 may be reduced according to
the reduction in the intervals of the grating grooves 912.
Because grating grooves 911 disposed on the left of the finger 930
are applied with an expansion force as the area of the flexible
film 900 disposed on the left of the finger 930 is expanded,
intervals of the grating grooves 911 may be increased in comparison
to the intervals of Case 1. In addition, a frequency reflected from
the grating grooves 911 may be increased according to the increase
in the intervals of the grating grooves 911.
Therefore, when the frequency of the grating grooves 911 is
increased and the frequency of the grating grooves 912 is reduced,
the position and shearing measurer 140 or the position and shearing
measurer 630 may determine that the finger 930 has input a shearing
force in a direction from a position of the grating grooves 911 to
a position of the grating grooves 912. In addition, the position
and shearing measurer 140 or the position and shearing measurer 630
may determine a degree of the shearing force input by the finger
930 based on a degree of the frequency change of the grating
grooves 911 and the grating grooves 912.
FIG. 10 illustrates a process of measuring a position of an item
touching an optical waveguide, according to example
embodiments.
The user may bring a finger 1030 into contact with a flexible film
1000 including an optical waveguide 1010 as shown in Case 1.
The user may push the flexible film 1000 by the finger 1030 as
shown in Case 2. Here, an area of the flexible film 1000
corresponding to a position of the finger 1030 may be contracted by
a pressure of the finger 1030.
Here, because grating grooves 1012 adjacent to the position of the
finger 1030 are provided with a contraction force according to the
contraction of the flexible film 1000, intervals of grating grooves
1011 may be reduced in comparison to intervals of Case 1. Frequency
reflected from the grating grooves 1011 may also be reduced
according to the reduction in the intervals of the grating grooves
1011.
The position and shearing measurer 140 or the position and shearing
measurer 630 may identify the grating grooves 1011 of which the
frequency is reduced and determine that the finger 1030 touches
positions of the grating grooves 1011.
The user may push a position between the grating grooves 1011 and
the grating grooves 1012 by the finger 1030 on the flexible film
1000 as shown in Case 3. The grating grooves 1011 and the grating
grooves 1012 adjacent to the position of the finger 1030 may be
contracted by the pressure of the finger 1030.
Accordingly, the intervals between the grating grooves 1011 and the
grating grooves 1012 may be reduced in comparison to intervals of
Case 1. Also, a frequency reflected from the grating grooves 1011
and the grating grooves 1012 may be reduced according to the
reduction in the intervals of the grating grooves 1011 and the
grating grooves 1012.
When the frequency of the grating grooves is reduced as in Case 3,
the position and shearing measurer 140 or the position and shearing
measurer 630 may identify the grating grooves of which the
frequency is reduced, and determine that the finger 1030 has
touched the position between the grating grooves 1011 and the
grating grooves 1012.
Here, the position and shearing measurer 140 or the position and
shearing measurer 630 may accurately determine the position of the
finger 1030 according to a frequency reduction ratio. For example,
when the frequency of the grating grooves 1011 and the frequency of
the grating grooves 1012 are reduced by the same ratio, the
position and shearing measurer 140 or the position and shearing
measurer 630 may determine that the finger 1030 is disposed in the
middle between the grating grooves 1011 and the grating groove
1012. When the frequency of the grating grooves 1011 is reduced
more than the frequency of the grating grooves 1012, the position
and shearing measurer 140 or the position and shearing measurer 630
may determine that the finger 1030 is disposed nearer to the
grating grooves 1011 between the grating grooves 1011 and the
grating grooves 1012.
FIG. 11 illustrates a bending measurement method according to
example embodiments.
In operation 1110, a frequency measurer 120 may measure a frequency
of light reflected from grating grooves of an optical
waveguide.
In operation 1120, a bending measurer may check whether the
frequency measured in operation 1110 is changed with respect to all
the grating grooves.
When the frequency measured in operation 1110 is changed with
respect to all the grating grooves, the bending measurer may
determine a flexible film including the optical waveguide or an
object to which the flexible film is attached is entirely bent, and
may perform operation 1130.
When frequency corresponding to a part of the grating grooves is
changed out of the frequency measured in operation 1110, the
bending measurer may determine that the flexible film including the
optical waveguide or the object to which the flexible film is
attached is partially bent or receives a touch input, and may
perform operation 1140.
In operation 1130, the bending measurer may determine bending of
the flexible film as a whole, including the optical waveguide or
the object to which the flexible film is attached.
In detail, when the frequency measured in operation 1110 is
increased, the bending measurer may determine that bending has
occurred at the object in an expanding direction of the optical
waveguide.
When the frequency measured in operation 1110 is reduced, the
bending measurer may determine that bending has occurred at the
object in a contracting direction of the optical waveguide.
Based on a change degree of the frequency measured by the frequency
measurer, the bending measurer may determine a degree of bending.
For example, when the frequency measured by the frequency measurer
is changed by a relatively large degree, the bending measurer may
determine that the object is bent by a large degree.
In operation 1140, the bending measurer may check whether the
change degree of the frequency measured in operation 1120 is
smaller than a threshold.
Here, when the change degree of the frequency measured in operation
1120 is greater than or equal to the threshold, the position and
shearing measurer may determine that the frequency change is caused
by partial bending of the object and perform operation 1150.
When the change degree of the frequency measured in operation 1120
is not smaller than the threshold, the position and shearing
measurer may determine that the frequency change is caused not by
bending of the object but by an item touching the optical waveguide
coupled with the object, and may perform operation 1160.
In operation 1150, the bending measurer may identify a position of
grating grooves corresponding to the changed frequency out of the
frequency measured in operation 1120 and determine that the bending
is generated at the identified position.
In operation 1160, the position and shearing measurer may determine
a position and a shearing force of the item touching the optical
waveguide 110 using the frequency measured in operation 1120.
Here, the position and shearing measurer may determine the position
of the item touching the object based on the frequency change
measured in operation 1120. For example, the position and shearing
measurer may identify a position of the grating groove
corresponding to the changed frequency out of the frequency
measured in operation 1120 and determine that the item touches the
object at the identified position.
The position and shearing measurer may determine the shearing force
of the item touching the object based on the frequency change
measured in operation 1120. For example, when a frequency
corresponding to a first grating groove among the grating grooves
is increased and a frequency corresponding to a second grating
groove is reduced, the position and shearing measurer may determine
that the shearing force is input by the item touching the object,
in a direction from the first grating groove to the second grating
groove.
FIG. 12 illustrates a pressure measurement method according to
example embodiments.
For example, FIG. 12 may illustrate a method of measuring a
pressure of an item touching an object by the measuring apparatus
shown in FIG. 6.
In operation 1210, the frequency measurer may determine frequency
of light reflected from grating grooves of the optical
waveguide.
In operation 1220, the position and shearing measurer may check
whether any frequency is changed in amplitude among the frequency
measured in operation 1210. When there is no frequency changed in
amplitude, the frequency measurer may repeat operation 1210.
In operation 1230, the position and shearing measurer may determine
a position of the item touching the object based on a change of the
frequency checked in operation 1220. For example, the position and
shearing measurer may identify a position of a grating groove
corresponding to the changed frequency out of the frequency
measured in operation 1210, and determine that the item touches the
object at the identified position.
In operation 1240, the position and shearing measurer may determine
the shearing force of the object based on a direction of the
frequency change checked in operation 1220. For example, when a
frequency corresponding to a first grating groove among the grating
grooves is increased and a frequency corresponding to a second
grating groove is reduced, the position and shearing measurer may
determine that the shearing force is input by the item touching the
object, in a direction from the first grating groove to the second
grating groove.
The methods according to the above-described example embodiments
may be recorded in non-transitory computer-readable media including
program instructions to implement various operations embodied by a
computer. The media may also include, alone or in combination with
the program instructions, data files, data structures, and the
like. The program instructions recorded on the media may be those
specially designed and constructed for the purposes of the example
embodiments, or they may be of the kind well-known and available to
those having skill in the computer software arts. Examples of
non-transitory computer-readable media include magnetic media such
as hard disks, floppy disks, and magnetic tape; optical media such
as CD ROM disks and DVDs; magneto-optical media such as optical
disks; and hardware devices that are specially configured to store
and perform program instructions, such as read-only memory (ROM),
random access memory (RAM), flash memory, and the like. The media
may be transfer media such as optical lines, metal lines, or
waveguides including a carrier wave for transmitting a signal
designating the program command and the data construction. The
computer-readable media may also be a distributed network, so that
the program instructions are stored and executed in a distributed
fashion. The program instructions may be executed by one or more
processors. The computer-readable media may also be embodied in at
least one application specific integrated circuit (ASIC) or Field
Programmable Gate Array (FPGA), which executes (processes like a
processor) program instructions. Examples of program instructions
include both machine code, such as produced by a compiler, and
files containing higher level code that may be executed by the
computer using an interpreter. The described hardware devices may
be configured to act as one or more software modules in order to
perform the operations of the above-described example embodiments,
or vice versa.
Although example embodiments have been shown and described, it
would be appreciated by those skilled in the art that changes may
be made in these example embodiments without departing from the
principles and spirit of the disclosure, the scope of which is
defined in the claims and their equivalents.
* * * * *
References